ip command

I am a new Linux user. How do I add a new or default gateway using route command on Linux operating systems? How can I use route command to show or set a new route on Linux based server or desktop system?

I‘ve recently installed Debian Linux 4.0 on my server and Ubuntu Linux 7.04 on Laptop. I would love to have a multiple IP address that I can use for verity of purposes. I would like to bind 4 IP’s to the ‘eth0′ device or NIC. How do I achieve this?